Method for manufacturing seamless powder-cored wire

Abstract

The invention discloses a manufacturing method of a seamless powder core welding wire, which comprises the following steps of: providing a metal strip, and rolling the metal strip into a strip structure with a groove; adding flux powder to the grooves of the metal strip; the metal strip is rolled and folded into a tubular structure with a water-drop-shaped cross section, and the closed opening position is located at the tip of the water-drop-shaped tubular structure; a metal strip is conveyed to a welding workbench, positioning wheels are used for positioning the metal strip, the positioning wheels comprise the upper positioning wheel and the lower positioning wheel, the wheel face of the upper positioning wheel is provided with a groove matched with the tip portion, and the tip portion of the metal strip is clamped. The wheel surface of the lower positioning wheel is provided with a groove matched with the thick part of the drop-shaped tubular structure and is attached to the thick part of the metal strip; the opening closing position is welded; and rounding rolling and drawing treatment are conducted, and the welding wire with the preset specification and size is manufactured. According to the manufacturing method of the seamless powder-cored wire, the welding defects of the seamless powder-cored wire in the manufacturing process can be effectively reduced, and the stability of the welding wire is improved.

Description

Technical Field

[0001] The invention relates to the technical field of welding wire preparation, and in particular to a method for manufacturing seamless powder cored welding wire. Background Art

[0002] Powder cored welding wire is increasingly used in the field of welding. It not only plays an important role in cladding and thermal spraying, but also has an increasing usage in steel structure manufacturing and additive manufacturing for ships, automobiles, aviation, etc. Powder cored welding wire is divided into two types according to the cross-sectional form: seamless powder cored welding wire and seamed powder cored welding wire. Figure 1 Shown is a cross-sectional photograph of a seamless powder cored welding wire, in which the outer skin is a tubular structure wrapping the flux core, and its cross section is a closed circular ring structure. Figure 2 These are cross-sectional photos of two types of seamless powder-cored welding wires. In the seamless powder-cored welding wire, there is an opening in the cross section of the tubular outer skin that wraps the flux core.

[0003] The openings of seamed powder-cored welding wire will retain impurities such as lubricating powder in the wire manufacturing process. At the same time, it is easier for the internal powder to absorb moisture during storage and use, making the wire surface more prone to rust, reducing the weldability of the wire, causing greater spatter and smoke, and during welding operations, the oxygen and hydrogen content in the weld layer will increase, reducing the mechanical properties of the weld layer.

[0004] Making the powder cored welding wire seamless can not only avoid the drawbacks of powder cored welding wire with seams, but the regular and smooth shape can also reduce the wear of the welding gun conductive tip. It is very suitable for welding situations with higher performance requirements, such as the aerospace field.

[0005] There are generally two ways to manufacture seamless powder cored welding wire. In the first way, a U-shaped metal strip, such as a stainless steel strip, is provided, flux powder is filled into the groove of the U-shaped metal strip, and then the U-shaped metal strip is rolled and closed, and then welding is performed on the opening or gap at the closed position, and then drawing is performed to form a seamless powder cored welding wire of the required specifications. In the second way, a metal tube is provided, flux powder is filled into the metal tube, and then the metal tube is drawn to obtain a seamless powder cored welding wire of the required specifications.

[0006] The second method has low processing efficiency, short wire length, high cost, and powder easily forms gaps and stratification in the tube. The first method has high processing efficiency, theoretically the wire length can be infinitely long, low cost, stable powder filling, and is suitable for mass production. Therefore, the industry generally adopts the first method to prepare seamless powder cored welding wire.

[0007] However, the length of the metal strip used to make the welding wire is relatively long during the processing, which can reach hundreds to thousands of meters. In the second processing method, it is very difficult to ensure that such a long weld is defect-free when welding the opening or gap of the strip at the closing part. In particular, the cross-section of the strip after closing and pressing is nearly circular or elliptical. The opening of the strip with this shape is easy to deflect, which is not conducive to the subsequent welding of the opening, and it is easy to cause welding defects, which in turn affects the stability of the welding wire performance.

[0008] Therefore, it is necessary to propose a method for manufacturing a seamless powder cored welding wire that reduces welding defects and improves welding wire stability. Summary of the invention

[0009] The main technical problem solved by the present invention is to provide a method for manufacturing a seamless powder cored welding wire, which can effectively reduce welding defects of the seamless powder cored welding wire during the manufacturing process and improve the stability of the welding wire.

[0010] In order to solve the above technical problems, the present invention provides a method for manufacturing a seamless powder cored welding wire, comprising the following steps:

[0011] Providing a metal strip, and rolling and deforming the metal strip into a strip structure having grooves extending along the length direction of the metal strip;

[0012] adding flux powder into the grooves of the metal strip;

[0013] The metal strip is rolled and closed into a tubular structure with a water drop-shaped cross section, and the closing position is located at the tip of the water drop-shaped tubular structure;

[0014] The rolled and closed metal strip is conveyed to the welding workbench, and the metal strip is positioned using positioning wheels, wherein the positioning wheels include an upper positioning wheel and a lower positioning wheel, the wheel surface of the upper positioning wheel has a groove matching the tip of the water drop-shaped tubular structure, and the wheel surface of the lower positioning wheel has a groove matching the thick part of the water drop-shaped tubular structure, the upper positioning wheel clamps the tip of the metal strip, and the lower positioning wheel fits the thick part of the metal strip;

[0015] Welding the joints of metal strips;

[0016] Rolling the metal strip into a circular shape;

[0017] The metal strip is drawn to produce welding wire of preset specifications and dimensions.

[0018] The beneficial effects of the present invention are as follows: before seamlessly welding the metal strip, the embodiment of the present invention processes it into a tubular structure with a teardrop-shaped cross section. When welding and sealing, a positioning wheel matching the teardrop-shaped structure is used to clamp the metal strip, thereby improving the stability of the position of the welding area during welding and thus improving the quality of welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a cross-sectional photograph of a seamless powder cored welding wire in the prior art.

[0020] Figure 2 This is a cross-sectional photo of a powder-cored welding wire with a seam in the prior art.

[0021] Figure 3 It is a schematic diagram of the structure of the metal strip after rolling according to an embodiment of the present invention.

[0022] Figure 4 It is a schematic diagram of the structure of the metal strip after being filled with powder core according to an embodiment of the present invention.

[0023] Figure 5 It is a schematic diagram of the structure of the metal strip after rolling and closing according to an embodiment of the present invention.

[0024] Figure 6 It is a schematic structural diagram of a metal strip after rolling and closing according to another embodiment of the present invention.

[0025] Figure 7 It is a schematic diagram of the wheel surface structure of the first closing wheel in the rolling closing step of an embodiment of the present invention.

[0026] Figure 8 It is a schematic diagram of the wheel surface structure of the second closing wheel in the rolling closing step of an embodiment of the present invention.

[0027] Fig. 9 It is a schematic diagram of the arrangement structure of the positioning wheel in the welding step of an embodiment of the present invention.

[0028] Fig.10 Schematic diagram of the structure of the positioning wheel according to an embodiment of the present invention.

[0029] Fig.11 It is a schematic structural diagram of a positioning wheel according to another embodiment of the present invention. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0031] The method for manufacturing a seamless powder cored welding wire according to an embodiment of the present invention comprises the following steps:

[0032] S1, providing a metal strip, and rolling and deforming the metal strip into a strip structure having grooves extending along the length direction thereof;

[0033] S2, adding flux powder into the grooves of the metal strip;

[0034] S3, rolling and closing the metal strip into a tubular structure with a water drop-shaped cross section, wherein the closing position is located at the tip of the water drop-shaped tubular structure;

[0035] S4, conveying the rolled and closed metal strip to the welding workbench, and positioning the metal strip using positioning wheels, wherein the positioning wheels include an upper positioning wheel and a lower positioning wheel, the wheel surface of the upper positioning wheel has a groove matching the tip of the water drop-shaped tubular structure, and the wheel surface of the lower positioning wheel has a groove matching the thick part of the water drop-shaped tubular structure, the upper positioning wheel clamps the tip of the metal strip, and the lower positioning wheel fits the thick part of the metal strip;

[0036] S5, welding the joint position of the metal strip;

[0037] S6, performing circular rolling on the metal strip to roll the metal strip into a circular tube shape;

[0038] S7, drawing the metal strip to make welding wire of preset specifications and sizes.

[0039] In step S1, refer to Figure 3 The metal strip 30 can be a stainless steel strip or a nickel alloy strip. The metal strip 30 is rolled by a rolling mill so that it has a groove 31 extending along the length direction of the strip. The cross section of the rolled metal strip can be designed to be U-shaped, and the groove is a U-shaped groove.

[0040] In step S2, please refer to Figure 4 , the flux powder 32 is filled into the groove 31 of the metal strip 30. The flux powder 32 may include conventional flux components such as a deoxidizer, an alloy powder, and a slag forming agent.

[0041] In step S3, please refer to Figure 5 The metal strip 30 filled with flux powder 32 is rolled and closed into a tubular structure with a water droplet-shaped cross section. The upper part of the cross section of the rolled and closed metal strip 30 is a tip 35, which is an inverted V-shaped structure; the lower part of the cross section of the metal strip 30 is a thick part 36, which is a semicircular arc structure. After the metal strip 30 is rolled and closed, its cross section forms an approximately closed structure, but it is difficult to ensure that the joint position is completely closed by the rolling process. In order to avoid the adverse effect of the existing tiny gap on the subsequent performance of the welding wire, it needs to be further closed by welding technology.

[0042] In a specific embodiment of the present invention, the rolling and closing step can also be configured to include two steps. In the first step, the metal strip 30 filled with flux powder is rolled and closed into a tubular structure with a teardrop-shaped cross section. Figure 6In the second step, the joint of the tip 35 of the metal strip 30 is further rolled to have a cross section with an outwardly protruding curled edge 33, and the curled edges 33 on both sides of the metal strip 30 to be closed are attached to each other.

[0043] Please refer to Figure 7 In the first stage of the rolling and closing step, the first closing wheel 40 is used to close the metal strip 30. The first closing wheel 40 includes a first upper closing wheel 41 and a first lower closing wheel 42. The cross section of the wheel surface of the first upper closing wheel 41 along its radial direction is a V-shaped groove 410. The cross section of the wheel surface of the first lower closing wheel 42 along its radial direction is a U-shaped groove 420. The first upper closing wheel 41 and the first lower closing wheel 42 cooperate with each other to close and roll the metal strip 30 into a teardrop-shaped structure in cross section.

[0044] Please refer to Figure 8 In the second stage of the rolling and closing step, the metal strip 30 is closed using the second closing wheel 50. The second closing wheel 50 includes a second upper closing wheel 51 and a second lower closing wheel 52. The cross section of the wheel surface of the second upper closing wheel 51 along its radial direction is a V-shaped groove 510. An opening 511 is provided at the bottom of the groove of the V-shaped groove 510 of the second upper closing wheel 51, and the opening 511 is used to roll and form the curling edge 33 of the metal strip 30 in the second stage of the closing step. The second lower closing wheel 52 has the same structure as the first lower closing wheel 42, and the cross section of the wheel surface of the second lower closing wheel 52 along its radial direction is a U-shaped groove 520. The second upper closing wheel 51 and the second lower closing wheel 52 cooperate with each other to further close the metal strip 30 at its closing position and roll out the curling edge 33.

[0045] In step S4, the rolled and closed metal strip 30 is transported to a welding workbench. Fig. 9 and Fig.10 The welding workbench (not shown) is provided with two groups of positioning wheels 60 and welding devices 70 in sequence along the conveying direction. The two groups of positioning wheels 60 are distributed before and after the welding point of the welding device 70. Each group of positioning wheels includes an upper positioning wheel 61 and a lower positioning wheel 62. The wheel surface of the upper positioning wheel 61 has a V-shaped groove in its radial cross section, and the wheel surface of the lower positioning wheel 62 has a U-shaped groove in its radial cross section. The V-shaped groove of the upper positioning wheel 61 engages with the closing position of the tip 35 of the metal strip 30, which can limit the deflection of the metal strip 30; the U-shaped groove of the lower positioning wheel 62 fits with the thick part 36 of the metal strip 30, which facilitates the rotation of the metal strip 30 and improves the deviation correction effect. Please refer to Fig.11 When the metal strip 30 has a curled edge 33 at the closing position, an opening 63 is provided at the bottom of the V-shaped groove on the wheel surface of the upper positioning wheel 61 , and the opening 63 engages with the curled edge 33 of the metal strip 30 .

[0046] In step S5, a welding device is used to weld the joint position of the metal strip 30. The welding process selects laser welding technology, that is, laser is selected as the welding heat source, because laser welding has small heat input, high energy density, stable laser ability, and can work for a long time, and is suitable for high-speed welding. In addition, laser welding does not require the wire to be connected to a power source, which can reduce the complexity of the equipment. In order to improve the quality of laser welding, the roller surface of the roller is redesigned.

[0047] The welding device comprises: a speed monitoring module, a visual image monitoring module, a human-computer interaction module, a central processing unit, a control module, a water cooling module, a laser generator, a laser deflection module, a protective gas module, a memory and a display.

[0048] The speed monitor is placed in front of the welding point to measure the speed of the metal strip 30 in real time and transmit the value to the central processor, which is displayed on the display and stored in the memory at the same time. It is a necessary condition for welding that the speed of the metal strip 30 reaches the set threshold range. When the speed of the metal strip 30 is lower than the lower threshold, welding stops.

[0049] The visual image monitoring module takes images of the welding points in real time and transmits the images to the central processing unit, which is displayed on the monitor and stored in the memory at the same time. The visual image monitoring module marks the spatial coordinates of the joint position of the metal strip 30 in real time. For the area where the joint position deviates from the preset welding position, the central processing unit combines the travel speed of the metal strip 30, deflects the laser through the laser deflection module, and adjusts the laser focus position in real time to complete the joint welding of these areas. If the joint position is within the allowable deviation range, the laser focus does not need to be moved. The deviation range of the joint position is within the set threshold range, which is a necessary condition for welding.

[0050] The human-machine interaction module inputs information to the central processor through the display to adjust or set the deviation threshold of the joint position and the start and stop of laser welding.

[0051] The control module manages the start and stop of the water chiller, laser generator, shielding gas and the laser deflection displacement.

[0052] In step S6, the welded metal strip is subjected to round rolling to be rolled into a preset welding wire shape.

[0053] S7, drawing the metal strip to make welding wire of preset specifications and sizes.

[0054] The manufacturing method of the seamless powder cored welding wire of the embodiment of the present invention adopts laser welding to close the welding wire, so that the adaptability of the wire making equipment is improved, and the composition, thickness and travel speed of the strip are adjusted in a wide range; the seamless wire can be manufactured after a slight modification on the existing powder cored wire equipment, and the popularization and application are strong. In laser welding, the wire does not need to be connected to the power supply, and the overall safety of the equipment is high. At the same time, when the welding wire is closed, the closing wheel and the wire positioning wheel are used to greatly reduce the change in the closing position of the welding wire, thereby improving the welding stability.

[0055] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a seamless powder cored welding wire, characterized in that: The following steps are involved: Providing a metal strip, and rolling and deforming the metal strip into a strip structure having grooves extending along the length direction of the metal strip; adding flux powder into the grooves of the metal strip; The metal strip is rolled and closed into a tubular structure with a water drop-shaped cross section, and the closing position is located at the tip of the water drop-shaped tubular structure; The rolled and closed metal strip is conveyed to the welding workbench, and the metal strip is positioned using positioning wheels, wherein the positioning wheels include an upper positioning wheel and a lower positioning wheel, the wheel surface of the upper positioning wheel has a groove matching the tip of the water drop-shaped tubular structure, and the wheel surface of the lower positioning wheel has a groove matching the thick part of the water drop-shaped tubular structure, the upper positioning wheel clamps the tip of the metal strip, and the lower positioning wheel fits the thick part of the metal strip; Welding the joints of metal strips; Rolling the metal strip into a circular shape; The metal strip is drawn to produce welding wire of preset specifications and dimensions.

2. The method for manufacturing a seamless powder cored welding wire according to claim 1, characterized in that: The metal strip is a stainless steel strip or a nickel alloy strip.

3. The method for manufacturing a seamless powder cored welding wire according to claim 1, characterized in that: The flux powder includes a deoxidizer, alloy powder and a slag forming agent.

4. The method for manufacturing a seamless powder cored welding wire according to claim 1, characterized in that: The upper part of the cross section of the metal strip after rolling and closing is a pointed part, presenting an inverted V-shaped structure; the lower part is a thick part, presenting a semicircular arc structure.

5. The method for manufacturing a seamless powder cored welding wire according to claim 1, characterized in that: The rolling closing step includes two steps: In the first step, the metal strip filled with flux powder is rolled and closed into a tubular structure with a teardrop-shaped cross section; in the second step, the joint at the tip of the metal strip is further rolled to have a cross section with an outwardly protruding curled edge, and the curled edges on both sides of the metal strip to be closed are fitted together.

6. The method for manufacturing a seamless powder cored welding wire according to claim 5, characterized in that: In the rolling closing step, the first closing wheel is used to close the metal strip in the first step. The first closing wheel includes a first upper closing wheel and a first lower closing wheel. The wheel surface of the first upper closing wheel has a V-shaped groove along its radial section, and the wheel surface of the first lower closing wheel has a U-shaped groove along its radial section. The first upper closing wheel and the first lower closing wheel cooperate with each other to close and roll the metal strip into a teardrop-shaped structure in cross section.

7. The method for manufacturing a seamless powder cored welding wire according to claim 6, characterized in that: In the rolling closing step, a second closing wheel is used to close the metal strip in the second stage. The second closing wheel includes a second upper closing wheel and a second lower closing wheel. The wheel surface of the second upper closing wheel is a V-shaped groove along its radial cross-section. An opening is provided at the bottom of the V-shaped groove of the second upper closing wheel. The curling edge of the metal strip is formed by rolling in the second stage of the closing step. The second lower closing wheel has the same structure as the first lower closing wheel.

8. The method for manufacturing a seamless powder cored welding wire according to claim 1, characterized in that: Two groups of positioning wheels and welding devices are sequentially arranged on the welding workbench along the conveying direction of the metal strip, and the two groups of positioning wheels are distributed before and after the welding point of the welding device; each group of positioning wheels includes an upper positioning wheel and a lower positioning wheel; the wheel surface of the upper positioning wheel has a V-shaped groove along its radial section, and the wheel surface of the lower positioning wheel has a U-shaped groove along its radial section, the V-shaped groove of the upper positioning wheel engages with the closing position of the tip of the metal strip, and the U-shaped groove of the lower positioning wheel fits with the thick part of the metal strip.

9. The method for manufacturing a seamless powder cored welding wire according to claim 8, characterized in that: An opening is provided at the bottom of the V-shaped groove of the upper positioning wheel, and the opening is engaged with the curling edge of the metal strip.

10. The method for manufacturing a seamless powder cored welding wire according to claim 1, characterized in that: The welding method is laser welding.

11. The method for manufacturing a seamless powder cored welding wire according to claim 10, characterized in that: In welding, the welding device used includes: a speed monitoring module, a visual image monitoring module, a human-computer interaction module, a central processing unit, a control module, a water cooling module, a laser generator, a laser deflection module, a shielding gas module, a memory and a display; the speed monitoring is placed in front of the welding point, measures the travel speed of the metal strip in real time, and transmits the value to the central processing unit, and displays it on the display and stores it in the memory; the visual image monitoring module takes real-time images of the welding point and transmits the image to the central processing unit, and displays it on the display and stores it in the memory; the visual image monitoring module marks the spatial coordinates of the joint position of the metal strip in real time, and for the area where the joint position deviates from the preset welding position, the central processing unit combines the travel speed of the metal strip, deflects the laser through the laser deflection module, adjusts the laser focus position in real time, and completes the welding of the joints in these areas; the human-computer interaction module inputs information to the central processing unit through the display, adjusts or sets the deviation threshold of the joint position and the start and stop of laser welding; the control module manages the start and stop of the water cooler, the laser generator, the shielding gas and the laser deflection displacement.

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